Time-resolved Fourier-transform infrared emission spectroscopy of Ag in the (1300–3600)-cm−1region: Transitions involvingfandgstates and oscillator strengths

Abstract

We report on a study of the emission spectra of Ag vapor in a vacuum (${10}^{\ensuremath{-}2}$ Torr) formed in ablation of an Ag metal target by a high-repetition rate (1.0 kHz) pulsed nanosecond ArF laser ($\ensuremath{\lambda}=193$ nm, output energy of 15 mJ). The time-resolved infrared emission spectrum of Ag was recorded in the 1300- to 3600-cm${}^{\ensuremath{-}1}$ spectral region using the Fourier transform infrared spectroscopy technique with a resolution of $0.02$ cm${}^{\ensuremath{-}1}$. The time profiles of the measured lines have maxima at 5\char21{}6 $\ensuremath{\mu}$s after a laser shot and display nonexponential decay with a decay time of 3\char21{}7 $\ensuremath{\mu}$s. The lines reported here are given with an uncertainty of 0.0005\char21{}0.016 cm${}^{\ensuremath{-}1}$. The line classification is performed using relative line strengths expressed in terms of transition dipole matrix elements calculated with the help of the Fues model potential; these calculations show agreement with the large experimental and calculated data sets available in the literature. In addition to these data we also calculate transition probabilities and line and oscillator strengths for a number of transitions in the 1300- to 5000-cm${}^{\ensuremath{-}1}$ range between $(4{d}^{10}){\mathit{nl}}_{j}$ states of Ag.